Hello, These patches make qemu generate an error on failure in setting a balloon value:
(qemu) balloon 400 Device 'balloon' has not been activated This can happen when the guest hasn't yet loaded a balloon driver. Previously, such a ballooning attempt didn't produce an error, but the virtio-balloon driver remembered the value nevertheless, causing a module load in the guest using the attempted balloon value originally. This may not be the desired course of action. I've re-used the QERR_DEVICE_NOT_ACTIVE error message, I think it fits in this case too. If not, let me know and I'll change it to something else. Please review and apply. Amit Shah (3): balloon: Make functions return 0 on OK, -1 on error. balloon: report error if ballooning operation fails virtio-balloon: report error if balloon driver in guest not available balloon.c | 19 ++++++++++++------- balloon.h | 2 +- hw/virtio-balloon.c | 6 +++++- 3 files changed, 18 insertions(+), 9 deletions(-) -- 1.7.7.3